1. Field of the Invention
The present invention relates to a vertical blind of electric type and, more particularly, to an electric blind which is electrically powered to have its slats traversed and titled.
2. Description of the Prior Art
Representatives of the vertical blind according to the prior art are disclosed in U.S. Pat. Nos. 4,306,608, 4,262,728 and 4,261,408, for example.
In these vertical blinds, generally speaking, two rods for traversing and tilting slats are rotatably borne in a casing frame in juxtaposition to each other such that the traverse rod is rotated by its drive motor to traverse a plurality of runners reciprocally in the casing frame and such that the tilt rod is rotated by its drive motor to tilt the slats reciprocally, end of which is suspended from the corresponding one of the runners.
Incidentally, in the vertical blind of electric type, the traverse drive motor is arranged in an upper portion of one end of the casing frame whereas the tilt drive motor is arranged in an upper portion of the other end of the casing frame such that the traverse drive motor and the traverse rod are interconnected at one end side of the casing frame by means of a belt and a pulley and such that the tilt drive motor and the tilt rod are also interconnected but at the other end side by means of a belt and a pulley.
Thus, in the prior art described above, the traverse drive motor, its rotation controller, and the drive transmitting means including the belt and the pulley for transmitting the driving power from the motor to the traverse rod are arranged at the one end side of the casing frame, whereas the tilt drive motor, its rotation controller, and the drive transmitting means including the belt and the pulley for transmitting the driving power from the motor to the tilt rod are arranged at the other end side of the casing frame. As a result, the drive motor unit has to be mounted on each of the two ends of the casing frame so that the size of the blind is accordingly enlarged. In addition, in case the casing frame has to be cut in conformity with the various standards of the site, all the drive motor, its rotation controller and the drive transmitting means at either end have to be once disassembled individually and are reassembled after the cutting operation. These works are so troublesome that the blind of the type under discussion is in fact customized at present, thus raising a problem of a low production efficiency.
In this blind, on the other hand, the casing frame is constructed such that the runners are positioned on the center line of the casing frame to run on guide rails.
With this construction of the prior art, the slats suspended from the runners have their two side edges projecting as far as the outside of the casing frame. As a result, a shield cover to be fitted on the outer wall of the casing frame is obstructed by the projected side edges of the slats so that it cannot be extended to below the casing frame, thus raising a problem that the light cannot be prevented without fail from breaking through the clearance between the casing frame and the slats. Since the runners are positioned on the center line of the casing frame, moreover, the electric blind cannot accommodate the whole drive unit in the casing frame so that the drive unit has to be partially arranged outside of the casing frame, and is accompanied by a problem that it is large-sized to have a rather ugly appearance.
In the bracket of the blind, on the other hand, as disclosed in U.S. Pat. No. 4,254,813, the hanger head is fitted in an adjustable manner on the bracket body, but the hanger hook is fixed in position on the hanger head. This in turn fixes the spacing between the one-and other-side clamping portions of the bracket. Moreover, the positioning of the bracket has to be made before the guide rails are attached. In case the mounting support face of a wall or the like is warped or bent, there arises another problem that the brackets cannot be regularly positioned but have to be attached over again.